What can the cosmos tell us about our past and future? Tom Sutcliffe and guests look skyward and deep into the quantum world to ask how much we can really know about the universe - and about ourselves.

Space scientist Maggie Aderin-Pocock, presenter of this year’s Royal Institution Christmas Lectures, shares her passion for inspiring the next generation to think big, as she explores the wonders of our solar system and the questions that still puzzle astronomers.

Physicist and cosmologist Paul Davies introduces his new book Quantum 2.0, charting the strange and revolutionary principles of quantum mechanics and how they are reshaping technology, science, and our understanding of reality itself.

From the Natural History Museum, Caroline Smith brings insights from meteorites — fragments of ancient worlds — and explains how these cosmic messengers help scientists search for life beyond Earth and piece together the story of our solar system’s origins.

Together, in Radio 4's weekly ideas discussion programme Start the Week, they consider the limits of knowledge: whether in decoding quantum mysteries, interpreting rocks from space, or imagining the motivations of those who first looked to the stars.

Producer: Ruth Watts